Just some background. Truck has a "hard-to-start" (long crank time) problem. I replaced the factory lift pump with a FASS pump. I see no diesel in the oil, no strange smoke, no error codes, and the truck runs great when it starts. The one certain thing is that when it has been running for a while, say from my house to work (20 mi), it is very hard to start. When I get in it in the morning when the engine is ambient temp, it starts up about like it should. SO cold, it's OK, but hot, it's not going to start right up. Temperature definitely makes a difference. I know in the system there is a CR fuel pressure sensor, a CR fuel pressure relief valve, the FCA on the CP3, the CP3 itself, and the injectors. (yes, and the ECM). Something in this chain operates differently when it gets hot.......but what? Anybody with a similar experience? I hate buying and changing out high-dollarparts at random.

Thanks,

Curtis

 

No codes...o.k.....do you have a fuel pressure guage? I see it says no mods in your sig, but had to ask. May have to get a fuel pressure guage to verify that and be able to move on to the next step. When it does start, is there any smoke out of the tail pipe? White, blue, black, anything different than when it starts cold? Could be the rail relief valve draining back or coolant temp sensor, intake air temp sensor, lots of things really. But lets start with the basics. Changed the fuel filter recently? That and then verify fuel pressure. ( lift pump pressure )

 

Also have the dealer do the injector leak down test. Could be one or more injectors is leaking and not allowing the CP3 pump to build enough rail pressure for starting.

MikeyB

 

No fuel pressure gauge (yet), no smoke at cold or hot. Another funny thing is that I still get about 21.5 mpg, which is the same as when it was brand new. Now, I haven't considered any of the other non-fuel related sensors. Anybody gotta rough idea what a dealer charges for a injector leakdown test?? I really really don't want to involve the dealer since it's out of warranty, but I will do what I have to do.

 

Leak down test at my dealer was about $100, I had four injectors fail the test, leaking in the neighborhood of 200 ml. Most dealers will give you a deal on 6 injectors as opposed to just replacing the bad ones. Plus you save the labor when the other (one) goes bad in a few months.

 

How is the fass turned on? Do you use the wait to start light?
I am just curious. Because when I get in a rush and do not use the wait to start light the trucks takes longer to start.

This is due to the fuel transfer pump which will run for a few second to prime the system when waiting for the light. This priming action would then tell all the other switches/sensor to close or activate. Allowing the truck to start.

Shawn

 

Had all 6 injectors replaced on friday. The rig starts so fast now it's hard to let go of the key quick enough. It was a lot of money but I don't know how well the first owner took care of changing the filters. I know how often I change them and hopefully I will not need to replace them again as long as I have the truck.

 

I have had the same problem in the shop. It has always been injectors.They leak through the return line.

 

How long are injectors supposed to last? Is frequent fuel filter changes the only thing I can do to prolong the life of the injectors?